We associated a cost of insertion to each pathway based on several criteria such as gene insertion cost, expression levels, enzyme efficiency and nominal fluxes.
Finally a low cost expression platform that permits the recovery of correctly folded immunoglobulin variable domains with correct disulfide bond formation is desirable.
We have established an automated, fast and flexible low-cost expression cloning approach requiring only vector and insert amplification by PCR and co-transformation of the products.
In conclusion, this is a simple, reliable, automated, robust, flexible and low-cost expression cloning approach in which PCR fragments are fused into an expression vector without unwanted amino acids.
The model assumes that there is a cost to expression and that expression levels are approximately optimized by natural selection.
To give the author of a work embodying such characters or situations ("idea" in copyright lingo) copyright protection beyond the form in which he molds them into a particular novel or story ("expression") would increase the cost of expression of later authors without generating offsetting benefits.
Codon usage tends to be more favorable at higher expression levels, so the total cost of expression, and hence the strength of selection for specific activity, increases less rapidly with expression level than it would without selection for codon choice.
This is because, on the simplest model, high expression of a gene will increase the cost of expression of all genes, leaving the relative marginal costs unchanged.
With these parameters, c = 1 for an equal mix of preferred and nonpreferred codons (Fop = 1/2), and the cost of expression with Fop = 1 (all preferred codons) is half the cost of expression with Fop = 0 (all nonpreferred codons).
